src/objectrenderer.h

   1 /**
   2  * @file objectrenderer.h
   3  * @brief Definition of ObjectRenderer class
   4  */
   5
   6 #ifndef _OBJECT_RENDERER_H
   7 #define _OBJECT_RENDERER_H
   8
   9 #include "ipdf.h"
  10 #include "graphicsbuffer.h"
  11 #include "shaderprogram.h"
  12 #include "bufferbuilder.h"
  13
  14
  15 namespace IPDF
  16 {
  17         class View;
  18         /**
  19          * Abstract Base class representing how a particular type of object will be rendered
  20          * Includes GPU rendering and CPU rendering
  21          * For GPU rendering, pass GLSL shader source files to constructor in the constructor of a base class
  22          *      To leave unimplemented, just pass NULL filename strings
  23          * For CPU rendering, implement RenderUsingCPU in the derived class
  24          *  To leave unimplemented, just call ObjectRenderer::RenderUsingCPU in the derived class
  25          * The View class uses ObjectRenderer's; see view.h
  26          */
  27         class ObjectRenderer
  28         {
  29                 public:
  30                         /** Construct the ObjectRenderer **/
  31                         ObjectRenderer(const ObjectType & type, const char * vert_glsl_file, const char * frag_glsl_file, const char * geom_glsl_file = "");
  32                         virtual ~ObjectRenderer() {}
  33
  34                         /**
  35                          * Use the GPU to render the objects - GLSL shader approach
  36                          * This way is definitely faster, but subject to the GPU's limitations on precision
  37                          */
  38                         virtual void RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id);
  39
  40                         /**
  41                          * Use the CPU to render the objects - "make a bitmap and convert it to a texture" approach
  42                          * This way is definitely slower, but gives us more control over the number representations than a GPU
  43                          */
  44
  45                         struct CPURenderTarget
  46                         {
  47                                 uint8_t * pixels;
  48                                 int64_t w;
  49                                 int64_t h;
  50                         };
  51                         struct PixelBounds
  52                         {
  53                                 int64_t x; int64_t y; int64_t w; int64_t h;
  54                                 PixelBounds(const Rect & bounds) : x(Double(bounds.x)), y(Double(bounds.y)), w(Double(bounds.w)), h(Double(bounds.h)) {}
  55                         };
  56
  57                         static Rect CPURenderBounds(const Rect & bounds, const View & view, const CPURenderTarget & target);
  58
  59
  60                         static void SaveBMP(const CPURenderTarget & target, const char * filename);
  61
  62
  63                         virtual void RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id) = 0;
  64
  65
  66
  67                         const ObjectType m_type; /** Type of objects **/
  68                 protected:
  69                         friend class View; //View is a friendly fellow in the world of IPDF
  70                         void PrepareBuffers(unsigned max_size);
  71                         void FinaliseBuffers();
  72                         void AddObjectToBuffers(unsigned index);
  73
  74                         /** Helper for CPU rendering that will render a line using Bresenham's algorithm. Do not use the transpose argument. **/
  75                         static void RenderLineOnCPU(int64_t x0, int64_t y0, int64_t x1, int64_t y1, const CPURenderTarget & target, const Colour & colour = Colour(0,0,0,1), bool transpose = false);
  76
  77                         ShaderProgram m_shader_program; /** GLSL shaders for GPU **/
  78                         GraphicsBuffer m_ibo; /** Index Buffer Object for GPU rendering **/
  79                         std::vector<unsigned> m_indexes; /** Index vector for CPU rendering **/
  80                         BufferBuilder<uint32_t> * m_buffer_builder; /** A BufferBuilder is temporarily used when preparing the ibo and std::vector **/
  81         };
  82
  83         /** Renderer for filled rectangles **/
  84         class RectFilledRenderer : public ObjectRenderer
  85         {
  86                 public:
  87                         RectFilledRenderer() : ObjectRenderer(RECT_FILLED, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl","shaders/rect_filled_geom.glsl") {}
  88                         virtual ~RectFilledRenderer() {}
  89                         virtual void RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
  90         };
  91         /** Renderer for outlined rectangles **/
  92         class RectOutlineRenderer : public ObjectRenderer
  93         {
  94                 public:
  95                         RectOutlineRenderer() : ObjectRenderer(RECT_OUTLINE, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl", "shaders/rect_outline_geom.glsl") {}
  96                         virtual ~RectOutlineRenderer() {}
  97                         virtual void RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
  98         };
  99         /** Renderer for filled circles **/
 100         class CircleFilledRenderer : public ObjectRenderer
 101         {
 102                 public:
 103                         CircleFilledRenderer() : ObjectRenderer(CIRCLE_FILLED, "shaders/rect_vert.glsl", "shaders/circle_frag.glsl", "shaders/circle_filled_geom.glsl") {}
 104                         virtual ~CircleFilledRenderer() {}
 105                         virtual void RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
 106         };
 107
 108         /** Renderer for bezier curves **/
 109         class BezierRenderer : public ObjectRenderer
 110         {
 111                 public:
 112                         BezierRenderer() : ObjectRenderer(BEZIER, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl", "shaders/bezier_texbuf_geom.glsl") {}
 113                         virtual ~BezierRenderer() {}
 114                         virtual void RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id);
 115                         virtual void RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
 116                         void PrepareBezierGPUBuffer(const Objects & objects);
 117                 private:
 118                         GraphicsBuffer m_bezier_coeffs;
 119                         GraphicsBuffer m_bezier_ids;
 120                         struct GPUBezierCoeffs
 121                         {
 122                                 float x0, y0;
 123                                 float x1, y1;
 124                                 float x2, y2;
 125                                 float x3, y3;
 126                         };
 127
 128                         GLuint m_bezier_buffer_texture;
 129                         GLuint m_bezier_id_buffer_texture;
 130
 131         };
 132
 133                 /** Renderer for filled circles **/
 134         class GroupRenderer : public ObjectRenderer
 135         {
 136                 public:
 137                         GroupRenderer() : ObjectRenderer(GROUP, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl", "shaders/rect_outline_geom.glsl") {}
 138                         virtual ~GroupRenderer() {}
 139                         virtual void RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
 140                         // do nothing on GPU
 141                         virtual void RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id) {}
 142         };
 143
 144 }
 145
 146 #endif //_OBJECT_RENDERER_H